5Dmk3 + 100mm Macro f2.8... How's the AF speed?

I posted this in the portrait forum but they don't seem to talk tech in there, so hope the mods don't mind a repost here.

I'm leaning toward getting the 100mm macro lens for both portrait/fashion and because I love macro. I heard this lens is a tad slow to AF but I heard the 5dmk3 is a fast AF camera so I'm wondering if it gets evened out.Yes I realize the 85mm is awesome, I'll get one later. I have a 50mm f1.4 that was 80mm on my crop 60D and want to try something new + I love macro.